[build]: enable docker in ram option for small disk device (#3279)

when device disk is small, do not unzip dockerfs.tar.gz on disk.
keep the tar file on the disk, unzip to tmpfs in the initrd phase.

enabled this for 7050-qx32

Signed-off-by: Guohan Lu <gulv@microsoft.com>

files/Aboot/boot0.j2

@@ -137,8 +137,10 @@ extract_image() {
     rootfs_type=`grep " $target_path " /proc/mounts | cut -d' ' -f3`
 
     info "Extracting $dockerfs from swi"
-    ## vfat does not support symbol link
-    if [ "$rootfs_type" != "vfat" ]; then
+    ## Unpacking dockerfs delayed
+    ## 1. when disk is vfat as it does not support symbolic link
+    ## 2. when disk is small, expand it into ramfs during initrd
+    if [ "$rootfs_type" != "vfat" -a x"$docker_inram" != x"on" ]; then
         mkdir -p "$image_path/{{ DOCKERFS_DIR }}"
 
         if [ -n "$install" ]; then
@@ -151,7 +153,7 @@ extract_image() {
     else
         ## save dockerfs archive in the image directory
         unzip -oq "$swipath" "$dockerfs" -d "$image_path"
-        info "Unpacking $dockerfs delayed to initrd because $target_path is $rootfs_type"
+        info "Unpacking $dockerfs delayed to initrd because $target_path is $rootfs_type or docker_inram is on"
     fi
 
     ## use new reduced-size boot swi
@@ -198,7 +200,8 @@ platform_specific() {
     if [ "$platform" = "raven" ]; then
         aboot_machine=arista_7050_qx32
         flash_size=2000
-        echo "modprobe.blacklist=radeon,sp5100_tco acpi=off" >>/tmp/append
+        docker_inram=on
+        echo "modprobe.blacklist=radeon,sp5100_tco acpi=off docker_inram=on" >>/tmp/append
     fi
     if [ "$platform" = "crow" ]; then
         aboot_machine=arista_7050_qx32s
@@ -296,6 +299,7 @@ write_boot_configs() {
         fi
     fi
 
+    mkdir -p "$image_path"
     mv /tmp/append $cmdline_image
     [ -e ${target_path}/machine.conf ] || write_machine_config
 }
@@ -391,12 +395,12 @@ if $do_install; then
             clean_flash
         fi
 
-        info "Installing image under $image_path"
-        extract_image
-
         info "Generating boot-config, machine.conf and cmdline"
         write_boot_configs
 
+        info "Installing image under $image_path"
+        extract_image
+
         run_hooks post-install
     else
         info "Using previously installed image"

files/initramfs-tools/arista-convertfs.j2

@@ -130,6 +130,9 @@ for x in "$@"; do
             x1="${x#loop=}"
             image_dir="${x1%/*}"
             ;;
+        docker_inram=*)
+            docker_inram="${x#docker_inram=}"
+            ;;
     esac
 done
 
@@ -217,9 +220,11 @@ err_msg="Error: mounting $root_dev to $root_mnt failed"
 cmd="mount -t ext4 $root_dev $root_mnt"
 run_cmd "$cmd" "$err_msg"
 
-err_msg="Error: extract docker directory"
-cmd="[ -f $tmp_mnt/$image_dir/{{ FILESYSTEM_DOCKERFS }} ] && rm -rf $root_mnt/$image_dir/{{ DOCKERFS_DIR }} && mkdir -p $root_mnt/$image_dir/{{ DOCKERFS_DIR }} && tar xzf $tmp_mnt/$image_dir/{{ FILESYSTEM_DOCKERFS }} -C $root_mnt/$image_dir/{{ DOCKERFS_DIR }} && rm -f $tmp_mnt/$image_dir/{{ FILESYSTEM_DOCKERFS }}"
-run_cmd "$cmd" "$err_msg"
+if [ x"$docker_inram" != x"on" ]; then
+    err_msg="Error: extract docker directory"
+    cmd="[ -f $tmp_mnt/$image_dir/{{ FILESYSTEM_DOCKERFS }} ] && rm -rf $root_mnt/$image_dir/{{ DOCKERFS_DIR }} && mkdir -p $root_mnt/$image_dir/{{ DOCKERFS_DIR }} && tar xzf $tmp_mnt/$image_dir/{{ FILESYSTEM_DOCKERFS }} -C $root_mnt/$image_dir/{{ DOCKERFS_DIR }} && rm -f $tmp_mnt/$image_dir/{{ FILESYSTEM_DOCKERFS }}"
+    run_cmd "$cmd" "$err_msg"
+fi
 
 err_msg="Error: copying files form $tmp_mnt to $root_mnt failed"
 cmd="cp -a $tmp_mnt/. $root_mnt/"

files/initramfs-tools/union-mount.j2

@@ -20,9 +20,17 @@ mount -n -o lowerdir=${rootmnt},upperdir=${rootmnt}/host/$image_dir/rw,workdir=$
 [ -b ${ROOT} ] || mdev -s
 ## Mount the raw partition again
 mount ${ROOT} ${rootmnt}/host
-## Mount the working directory of docker engine in the raw partition, bypass the overlay
+
 mkdir -p ${rootmnt}/var/lib/docker
-mount --bind ${rootmnt}/host/$image_dir/{{ DOCKERFS_DIR }} ${rootmnt}/var/lib/docker
+if [ -f ${rootmnt}/host/$image_dir/{{ FILESYSTEM_DOCKERFS }} ]; then
+    ## mount tmpfs and extract docker into it
+    mount -t tmpfs -o rw,nodev,size={{ DOCKER_RAMFS_SIZE }} tmpfs ${rootmnt}/var/lib/docker
+    tar xz --numeric-owner -f ${rootmnt}/host/$image_dir/{{ FILESYSTEM_DOCKERFS }} -C ${rootmnt}/var/lib/docker
+else
+    ## Mount the working directory of docker engine in the raw partition, bypass the overlay
+    mount --bind ${rootmnt}/host/$image_dir/{{ DOCKERFS_DIR }} ${rootmnt}/var/lib/docker
+fi
+
 ## Mount the boot directory in the raw partition, bypass the overlay
 mkdir -p ${rootmnt}/boot
 mount --bind ${rootmnt}/host/$image_dir/boot ${rootmnt}/boot

installer/x86_64/install.sh

@@ -479,15 +479,20 @@ else
 fi
 
 # Decompress the file for the file system directly to the partition
-unzip -o $ONIE_INSTALLER_PAYLOAD -x "$FILESYSTEM_DOCKERFS" -d $demo_mnt/$image_dir
-
-if [ "$install_env" = "onie" ]; then
-    TAR_EXTRA_OPTION="--numeric-owner"
+if [ x"$docker_inram" = x"on" ]; then
+    # when disk is small, keep dockerfs.tar.gz in disk, expand it into ramfs during initrd
+    unzip -o $ONIE_INSTALLER_PAYLOAD -d $demo_mnt/$image_dir
 else
-    TAR_EXTRA_OPTION="--numeric-owner --warning=no-timestamp"
+    unzip -o $ONIE_INSTALLER_PAYLOAD -x "$FILESYSTEM_DOCKERFS" -d $demo_mnt/$image_dir
+
+    if [ "$install_env" = "onie" ]; then
+        TAR_EXTRA_OPTION="--numeric-owner"
+    else
+        TAR_EXTRA_OPTION="--numeric-owner --warning=no-timestamp"
+    fi
+    mkdir -p $demo_mnt/$image_dir/$DOCKERFS_DIR
+    unzip -op $ONIE_INSTALLER_PAYLOAD "$FILESYSTEM_DOCKERFS" | tar xz $TAR_EXTRA_OPTION -f - -C $demo_mnt/$image_dir/$DOCKERFS_DIR
 fi
-mkdir -p $demo_mnt/$image_dir/$DOCKERFS_DIR
-unzip -op $ONIE_INSTALLER_PAYLOAD "$FILESYSTEM_DOCKERFS" | tar xz $TAR_EXTRA_OPTION -f - -C $demo_mnt/$image_dir/$DOCKERFS_DIR
 
 if [ "$install_env" = "onie" ]; then
     # Store machine description in target file system

onie-image.conf

@@ -24,6 +24,9 @@ FILESYSTEM_DOCKERFS=dockerfs.tar.gz
 ## docker directory on the root filesystem
 DOCKERFS_DIR=docker
 
+## docker ramfs disk space
+DOCKER_RAMFS_SIZE=800M
+
 ## Output file name for onie installer
 OUTPUT_ONIE_IMAGE=target/sonic-$TARGET_MACHINE.bin